Economizing the use of nitrogen fertilizer in wheat production through enriched compost

Manipulation of organic wastes and their composts as a source of organic matter (OM) and nutrients is imperative for sustainable agriculture. Further, the fortification of composts with chemical fertilizer enhances agronomic effectiveness of both by reducing the amount of fertilizer and improving the quality of compost. The present study aimed to explore the potential of organic and chemical nutrient sources with their optimal application and integration for sustainable wheat production. Accordingly, waste fruits and vegetables were collected, dried, ground and processed in a composting vessel. During the enriched composting, waste material (300 kg) was fortified with 30 kg N, i.e. 25% of the standard rate (120 kg N ha-1) of N fertilizer. Treatments for both greenhouse and field experiments using wheat (Triticum aestivum L.) included: control (without any compost or N fertilizer), compost (non-enriched), fertilizer N 120 (120 kg N ha-1), nitrogen-enriched compost (NEC), NEC+N 30 (30 kg N ha-1) and NEC+N 60 (60 kg N ha-1). Application rate of composts (non-enriched or enriched) was 300 kg ha-1 in the respective treatments. Phosphorus and potassium fertilizers were applied at 90 kg P2O5 ha-1 and 60 kg K2O ha-1, respectively in all treatments. The crop was grown to maturity, and data on wheat growth and yield attributes were recorded. Application of NEC significantly improved the growth, yield and N, P and K contents of wheat compared with compost and control treatments. The performance of NEC+N 60 was statistically similar to that of fertilizer N 120. Economic analysis also revealed the superiority of NEC+N 60 over other treatments in terms of net return and relative increase in income; however, the value/cost ratio was highest with NEC alone. For effective and economical use of N fertilizer, it is suggested to integrate N fertilizer at reduced rates with NEC. Through enriched compost, application rates can be decreased from tonnes to kilograms per hectare, and dependence on chemical fertilizer can be reduced to a certain extent. So the approach is farmer friendly as it lowers compost application rates, and is economically acceptable as it saves N fertilizer. It is also environmentally sustainable due the recycling of organic waste and possible reduction of N losses to the environment. Thus, the study has wide application in the global environment and fertilizer market.